Twin DF 140 vs Twin 150 opti/etec vs Single 300HP on 21ft deep v glass boat

[WildFishExpeditions]

yeah to be fair its probably the worst boating article I have ever read. Very little content. I skim read it the first time a week ago, then posted it up here thinking it would be useful. On a more thorough read i can confirm that is more an exercise in mutual masturbation in contrast to an actual boat review.

I dont really know what to make of the shootout. I suspect that two motors would have better hole shot due to having more blade pushing water. I would have expected the 300 to do better at top speed due to less resistance. One motor is more economical than two , i can dig that.

[up the creek]

yeah to be fair its probably the worst boating article I have ever read. Very little content. I skim read it the first time a week ago, then posted it up here thinking it would be useful. On a more thorough read i can confirm that is more an exercise in mutual masturbation in contrast to an actual boat review.

lol wildfish nice way of putting it..

[ranmar850]

This whole "holeshot" business is getting out of hand, like a lot of yankee bullshit endlessly repeated on the internet. Are you pulling a single skier up? Do you really need to get to an identical top speed 1.6 seconds faster? Are you running this thing on a bloody dragstrip? Yes, if need to do bar runs, you need acceleration, at times, but anything with that sort of horsepower will have enough. If it hasn't, you're doing it wrong.. So many other things are far more important over an extended period of ownership.

[Vromme]

up the creek
Money is not that much of a concern at this stage. The redundancy of the 2^nd engine isn’t a major factor for me as to get home at planing speed I would have to change the prop, can be a pita in poor conditions.

WildFishExpeditions
Have seen that vid/article and spoken to a couple of the guys involved. Part of my reasoning for looking at twins seriously, particularly the extra stability whilst driving and at rest.

Andy56 I would have concluded the same as you but judging by the 150 vs 300 comparison on the youtube link some of the results were opposite to what I would have assumed. No doubt other factors come into play (even how motors have been installed). ranmar850 I agree in general that holeshot can just be another wank factor. However the boat needs to be driven hard (well to get the most out of it). It is good to have plenty of instant power at hand, if for nothing else other than smile factor. I found this on another thread: model, displacement, KW, rpm, torque, rpm DF115/DF115Z 1950 84.58 5500 159 4500 DF140/DF140Z 2044 102.97 6000 165 4500 DF100 1950 73.55 5500 150 4000 DF150/DF150Z 2867 110.33 5500 235.2 4500 DF175/DF175Z 2867 128.71 5800 245 4500 DF200/DF200Z 3614 147.1 5500 307.7 3500 DF225/DF225Z 3614 165.49 5500 311.6 4500 DF250/DF250Z 3614 183.88 5800 313.6 4500 DF250S 4028 183.88 5800 343.2 4000 DF300/DF300Z 4028 220.65 6000 343.2 4500 I know guys who have upgraded from 115 to 140 and didn’t notice much of a difference. If above is correct it would explain why, bugger all dif in torque between 115 to 140 and then the bigger jump to 150hp. Interesting though that twin 140’s is only a little under a single 300 in torque. May answer my concern there.

[WalFish]

Torque is a product of bore and stroke more than anything else, hence why the 115 and 140 Suzi, with the same block have similar figures. Same same with the 150 and 175.

[WildFishExpeditions]

100% true.

This whole "holeshot" business is getting out of hand, like a lot of yankee bullshit endlessly repeated on the internet. Are you pulling a single skier up? Do you really need to get to an identical top speed 1.6 seconds faster? Are you running this thing on a bloody dragstrip? Yes, if need to do bar runs, you need acceleration, at times, but anything with that sort of horsepower will have enough. If it hasn't, you're doing it wrong.. So many other things are far more important over an extended period of ownership.

[up the creek]

bro if you got the cash and want overkill power then go bigger then 140hp suzis and you can always use 3/4 throttle, guess that way they wont work hard. and it sounds like you want more then the 140s suzis by some of your replies.if the boat can take the weight go 4 it. at least you wont have to rip em off and all the costs involved if the 140s dont have. (in your words) the smile factor lol. and boys we aint no yankie wankies but it is aussie blood to over pony our toys just a little lol..

[WildFishExpeditions]

yeah agree. there will certainly be a performance increase going to the 300 or 2 X 150hp, but its only good if you actually need it or want it. When I bought my boat I was looking at a package with a 140 suzuki. the boat builder told me to 100% dont get one as it wouldnt have the torque to push my hull because of the small 2L block, we decided the 3L merc 150 was the best option and its great. So yeah there would be a difference between twin 140 and twin 150, as it is torque over hp.

having said that the 140 would be a great fit and anything bigger you could argue is overkill on a 21ft hull. My hull is 22ft and the single 150 pushes is like a demon. But as I have stated in previous posts I have lost count of the number of punters who look at my boat and go "jeez 150hp too small for that hull" "couldnt get away with less than 200hp for that hull" amazing how many people think they know more about your boat than your do.... point is you dont need the max HP to get great performance out of a hull. I could have gone to 200hp, but for what gain? it does almost 50 miles an hour with the 150. I did see an identical hull of mine with a 200 V6 yam and it had a permatrim on it because it was too heavy on the transom. So going max HP can be bad just as many times as it can be good.

the twin 140 will push the hull to close to 80kmh and have all the torque you need. Id be very surprised if you ever felt like you needed more power than that.

having said that how does the 140 suzuki price up? Brisbane yamaha have the 130hp for $14,500 and the 300hp for 28,000 so you dont save much either way on initial purchase. probably not much between the 140 Suzuki and 130 Yamaha either.

bro if you got the cash and want overkill power then go bigger then 140hp suzis and you can always use 3/4 throttle, guess that way they wont work hard. and it sounds like you want more then the 140s suzis by some of your replies.if the boat can take the weight go 4 it. at least you wont have to rip em off and all the costs involved if the 140s dont have. (in your words) the smile factor lol. and boys we aint no yankie wankies but it is aussie blood to over pony our toys just a little lol..

[Chimo]

Interesting numbers NB not a direct comparison but still interesting IMHO http://www.thehulltruth.com/boating-...l#post10016975

[Vromme]

Up creek,

As in my original post – the main restricting factor to engine/s decision is max weight on transom.
For twins:
140/115 fourstroke (Yam/Suz/Merc) 150hp up are too heavy
150/175 two stroke (Opti/Etec)

Single
Any of the above manufacturers

I like to have plenty of power. I currently own a 17 foot boat (heavy Seadevil) with a 115 HO Etec on it and find it only just acceptable. Would prefer more power esp when loaded or pulling skiers.

WildFishExpeditions
The 150’s are known to be solid torquey engines (compared to 140’s). Twin 150s would be perfect setup from what I can gather – just too heavy in 4 stroke!
Twin 140’s don’t work out that much more than a single 300 (a bit more in fitting/rigging also). Optis are similar in 150 (more $ for 175) Not sure about Etec yet as havent priced them.
I’d prefer to pay a little extra and get what ticks the boxes.


Good report Chimo.

I have never complained nor heard of someone else complaining about having too much power (obviously as long as not too much weight on transom).

Blokes I talk to with higher HP on boats not only get better performance/jump on plane/smile factor but often better fuel econ (esp at decent speeds).

[Chimo]

300 HP G2

253 Kgs

http://www.evinrude.com/en-US/engine...-hp.html#tab=5

Fitted to an hydraulic jack plate lifts it for shallow water and still under weight

Probably worth some consideration.

Cheers
Chimo

[Cape Crusader]

Even the 140's are going to be pushing your 400kg limit, which may or may not be a problem, depending on the boat?
Definitely talking a different weight class or 2 from the yalta, but, more info could help those with experience to comment
Cheers
Rod

[up the creek]

if your restricted to 140s weight wise in the 4 stroke and the 150 in the 2 stroke is not really what u want then is it not coming closer to considering a single 300hp 4 stroke it ticks all the boxes and if that thing dont punch you back in your seat id be suprised???????

[scottar]

It's going to depend on how you want to drive your boat. The faster you go, the less critical transom weight becomes - until you reach the point you leave the water. If you are going to drive it like you stole it all the time, then the advantages of twins will make up for the (potentially) 150kg weight penalty. If you want to be able to slow down and still maintain an economical plane when it gets really snotty, the extra transom weight will hurt. Personally, I don't buy into the whole "it gets better the harder you push it argument" and no matter how good the hull, they all have a point where slowing down is not only good seamanship but a necessity - I've seen the videos of the masochists in the go fast spearo rigs holding on for dear life. Can the boats handle it - for sure - but people will break before the boat does. Sit down and have a good think about how you use your boat and make the call.

[WildFishExpeditions]

well said about how you drive your boat. cant remember if this has been covered yet, but is fuel cost a factor? I imagine the 140s would be save a fair bit of fuel compared to an opti/etec 150. as i said I have the 150 merc, my friend has the 140 suzuki. on a days game fishing I will burn maybe 20L more than him. which is pretty normal, as I have a heavier boat and we are comparing a 2L engine to a 3L engine. Not sure if that is a factor or not.

It's going to depend on how you want to drive your boat. The faster you go, the less critical transom weight becomes - until you reach the point you leave the water. If you are going to drive it like you stole it all the time, then the advantages of twins will make up for the (potentially) 150kg weight penalty. If you want to be able to slow down and still maintain an economical plane when it gets really snotty, the extra transom weight will hurt. Personally, I don't buy into the whole "it gets better the harder you push it argument" and no matter how good the hull, they all have a point where slowing down is not only good seamanship but a necessity - I've seen the videos of the masochists in the go fast spearo rigs holding on for dear life. Can the boats handle it - for sure - but people will break before the boat does. Sit down and have a good think about how you use your boat and make the call.